Hello, I am a college student with a love of photography. I currently work for my school's football team, which is fast paced and usually well-lit since most games are in the early afternoon. I have been offered a job from a communications director in the athletic department to shoot all sports. I am interested in buying a lens that will allow me to shoot basketball, volleyball and swimming/diving. A friend suggested a 70- 200mm f/4 or 2.8. I am still very new to photography so I'm not sure what to be looking for. I currently have a Canon EOS Rebel XS, so it's not a super fancy camera. I would appreciate any feedback you can give me, especially about which one of the lenses my friend recommended is better or if I should be looking into a different one. Thanks, Alysia H.